THE TACTILE SENSORY INNERVATION OF THE GLABROUS SKIN OF THE

The concept o f act ive touch i s i n t ima te l y l inked w i th the func t ion o f the human hand (Ref. 16). Although many aspects of ac t ive touch involve very com-plex funct ions i t i s obvioys t h a t a basic element must be the input t o the cent ra l nervous sys,them provided by the f i r s t order af ferents. The present ". n repo r t centres upon the t a c t i l e sensory innervat ion of, the human hand. T a c t i l e sensory mechanisms may be def ined as those which provide in format ion on the presence and charac ter is t i cs o f mechanical events a t the body surface. I n humans, these mechanisms produce sensations which range from those resu l-t i n g from passive touching1 t o de ta i led and complex perceptive experiences o f the shape, form, size, mechanical proper t ies and surface s t ruc ture o f physical objects as they are ac t i ve l y explored. It seems l i k e l y t ha t several types o f peripheral sensory un i t s contr ibute t o sensations of t h i s nature. One main group i s obviously the sensory u n i t s which have terminals i n the sk in and the sup6rf i c i a l subcutaneous tissues. Over the 1 as t decades evidence has bee